I started out using their 'free' membership...I started a simple family tree. As the years went by, I upgraded to a paid membership because I wanted to access to more documents. I've also found other sites which provide great resources...one of said sites is...familysearch.org
This offers ample free resources which can help one build a substantial family tree.
One of the blessings of researching your family tree is that you find relatives you didn't know you had. Just recently, while I was in Denver, I was contacted by someone who was researching my gr-grandfather's family....I had been told my gr-grandfather had brothers....but I never knew what became of them. They were from Chicago....only my gr-grandfather came to Washington State....now suddenly I was introduced to a 'lost branch' of my family tree.
Amazingly, we both realized that we were in Colorado at the same time. We made plans to meet up...can you see the family resemblance? Our gr-grandfathers were brothers.
The Chezsven Blog has a great story about cousins meeting up. You need to go and read about it at the blog update In which Sven meets his first cousin. An absolutely amazing story about finding family connections.
If you haven't ever dug around in your family roots...maybe you should consider starting today!